Field of the Invention
The present invention relates to an image forming apparatus using an electrophotographic image forming system (an electrophotographic process) and a developing device used in an image forming apparatus.
The image forming apparatus forms an image on a recording material (a recording medium) using the electrophotographic process. Examples of the image forming apparatus include a printer (a laser beam printer or a light-emitting diode (LED) printer), a copying machine, a facsimile apparatus, a word processor, and a multifunction peripheral (a multifunction printer) including these apparatuses.
Further, the developing device is a device for developing, using a developer, an electrostatic latent image formed on an electrophotographic photosensitive drum (hereinafter referred to as a “photosensitive member”) as an image bearing member. The developing device includes a developing unit, a developing frame member for supporting the developing unit, and components related to the developing unit. Examples of the developing unit include a developing roller as a developer bearing member and a developing blade as a developer regulating member.
Description of the Related Art
The image forming apparatus, such as a printer, using the electrophotographic process uniformly charges the photosensitive member. Then, the image forming apparatus selectively exposes the charged photosensitive member to form an electrostatic latent image on the photosensitive member. Then, using toner as a developer, the image forming apparatus visualizes as a toner image the electrostatic latent image formed on the photosensitive member. Then, the image forming apparatus transfers the toner image formed on the photosensitive member onto a recording material, such as a recording sheet and a plastic sheet, and applies heat and pressure to the toner image transferred onto the recording material to fix the toner image to the recording material, so that the image is recorded.
Generally, such an image forming apparatus requires maintenance of various process units used for the electrophotographic process. Examples of the process units include a charging unit for acting on a photosensitive member, a developing unit, and a cleaning unit. To facilitate maintenance of these various process units, a method for integrating the photosensitive member, the charging unit, the developing unit, and the cleaning unit into a cartridge to be attachable to and detachable from the main body of an image forming apparatus is put to practical use. According to this cartridge method, it is possible to provide an image forming apparatus excellent in usability.
The configuration of a cartridge, a drum cartridge including a photosensitive drum, a developing cartridge as a developing device including a developing unit, and a toner cartridge for supplying a developer, are known.
As discussed in the publication of Japanese Patent Application Laid-Open No. 2013-182036, there is a developing cartridge including a developing unit pivotably supporting a developing roller, and a frame pivotably supporting both end portions of the developing unit. In such a configuration, the frame is positioned relative to the main body of an image forming apparatus so that the developing unit can pivot, and the developing roller can abut a photosensitive drum and be separate from the photosensitive drum.